Quasi-Cylindrical Cargo Container and Construction

ABSTRACT

A quasi-cylindrical cargo container is formed of a plurality of rigid, curved panels together forming first and second semi-cylindrical shells, and a plurality of rigid, flat extension panels bridging the first and second semi-cylindrical shells. A method of manufacturing the container includes forming the first and second semi-cylindrical shell from the curved panels, forming the quasi-cylindrical shell from the first and second semi-cylindrical shells and the flat extension panels, forming collars conformably encompassing the quasi-cylindrical shell, constricting the collars to compress joints formed at abutting edges of pairs of adjacent panels, rolling the shell and collars sequentially to bring the joints to a lower position, welding inside seams of the joints when at the lower position, removing the collars, rolling the shell sequentially to bring the joints to an upper position, and welding outside seams of the joints when at the upper position.

RELATED APPLICATIONS

The present application is a continuation of, and claims benefit ofpriority to, U.S. patent application Ser. No. 16/649,497 filed on Mar.20, 2020, which is a U.S. National Phase Application under 35 U.S.C. §371 of International Application No. PCT/CA2018/050730 filed on Jun. 15,2018, which (1) claims the benefit of priority to U.S. ProvisionalPatent Application Ser. No. 62/562,001 filed on Sep. 22, 2017, and (2)is a continuation-in-part of International Application No.PCT/CA2017/051544 filed on Dec. 19, 2017, which also claims the benefitof priority to the aforesaid U.S. Provisional Patent Application Ser.No. 62/562,001 filed on Sep. 22, 2017, as well as to U.S. ProvisionalPatent Application Ser. No. 62/436,960 filed on Dec. 20, 2016, theentire disclosures of which are all expressly incorporated by referenceherein.

FIELD

The present disclosure relates generally to cylindrical cargo containersincluding cylindrical cargo containers for tanker trucks, trailers, andrailcars, as well as tanker trucks, trailers, and railcars havingcylindrical cargo containers.

BACKGROUND

Cylindrical cargo containers, such as the containers for tanker (ortank) trucks, trailers, and railcars, are widely used to transportvarious materials such as liquefied loads, dry bulk cargo, or gases onroads or rails. Whether incorporated in a tanker truck where thecontainer is mounted on a chassis and wheeled suspension commonly withthe truck, or a tanker trailer where the container is mounted on its ownchassis and wheeled suspension which is towed by a tractor, or arailroad tanker car, the container is typically cylindrical in shape andis mounted on and supported by a chassis and wheeled suspension. Otherconfigurations are possible.

Cylindrical cargo containers have many advantages which explain theirwidespread use. Based on simple geometry, for any given volume acylinder has a smaller surface area than a typical rectangular,box-shaped cargo container. As such, all other factors being equal, acylindrical container can have both a higher ratio of cargo weight tocontainer weight, and of cargo weight to container materials than acontainer of another shape. Moreover, cylindrical containers typicallyhave a more aerodynamic shape. Both of these factors result in a lessertowing or carrying load, and thus lesser truck or tractor powerrequirements, and better fuel economy.

Typically, such cylindrical containers have a construction including askin formed of a rigid and resilient plate material, usually metal, suchas rolled sheet steel or aluminum, and a frame structure, such asannular and longitudinal ribbed beam structure, which may includevertical bands or ribs, to provide shape and strength, and to supportthe skin, which is affixed to the frame, sometimes by welds. In othercases, a less sturdy and resilient material is used, such as fiberglassor reinforced plastic. In any event, the frame is typically mounted onand supported by the chassis of the truck, trailer, or railcar, and thusthe weight of any load contained by the tank is communicated to thechassis ultimately by this frame.

While sometimes the structural frame is disposed at least partly outsideof the sheet metal skin, such that at least part of the structural frameis exposed to the outside, doing so usually has the disadvantage ofdegrading the aerodynamics of the container resulting from windresistance at the projecting portions. As such, in many cases, thestructural frame is completely or mostly enveloped by the sheet metalskin. In some cases, doing so presents a different kind of disadvantage,including for example reduction of the useful volume of the container,or inclusion of obstructions within the container which may impedemovement of its contents.

Moreover, in connection with any type of cargo, it is desirable toachieve yet greater efficiencies and advantages from improvedconstruction and use of cylindrical containers which reduce cost andprovide new and enhanced uses.

U.S. Provisional Patent Application No. 62/562,011 and WIPOInternational Patent Application No. PCT/CA2017/051544, the entirety ofboth of which is incorporated herein by reference, discloses acylindrical cargo container and method of construction which overcomesmany of the above-described drawbacks, and provides further advantages.A cylindrical cargo container is formed from a plurality of longitudinalpanels having a common curvature, each of which has the shape of acylinder segment, and thus when assembled form a cylindrical tube. Amethod of manufacturing the cargo container includes providing a cradleformed from a first set of ring segments and laying a first set of thepanels in the cradle to form a first semi-cylindrical shell, placing aspacer in the first semi-cylindrical shell, laying a second set of thepanels atop the first semi-cylindrical shell and the spacer to form thecylindrical shell, laying a second set of ring segments atop the secondsemi-cylindrical shell and the first set of ring segments to form aplurality of collars, constricting the collars to compress longitudinaljoints between the panels, welding inside seams of the joints, removingthe collars, and welding outside seams of the joints. The container mayform a part of a tanker truck, trailer, or railcar.

While the cylindrical container, tanker truck, trailer, and railcardisclosed in U.S. Provisional Patent Application No. 62/562,011 and WIPOInternational Patent Application No. PCT/CA2017/051544 overcomes many ofthe drawbacks and provides further advantages over prior teachings, thetotal capacity thereof is less than that of a conventional rectangularcargo container for a given width. The width of cargo containerspermitted on roads or rails is typically governmentally regulated,thereby limiting the permitted capacity of cylindrical cargo containers.

There thus remains a need for efficient and reliable methods ofmanufacturing cargo containers, including cargo containers withincreased cargo capacity.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the attached Figures.

FIG. 1 shows a first perspective view of a quasi-cylindrical cargotrailer having a container formed of longitudinal panels.

FIG. 2 shows a side view of the quasi-cylindrical cargo trailer of FIG.1 .

FIG. 3 shows a cross-sectional view of a container of the cargo trailerof FIG. 1 .

FIG. 3A is a detail view thereof showing a tongue-and-groove joint.

FIG. 4 shows a first perspective view of a quasi-cylindrical cargotrailer having a container formed of longitudinal extruded panels.

FIG. 5 shows a side view of the quasi-cylindrical cargo trailer of FIG.4 .

FIG. 6 shows a cross-sectional view of a container of the cargo trailerof FIG. 4 .

FIGS. 6A through 6C are detail cross-sectional views of individualextruded panels forming the container.

FIG. 7 shows a perspective view of a quasi-cylindrical shell formed ofcurved panels and flat extension panels encompassed by a plurality ofcollars.

FIG. 8 shows a cross-sectional view of the quasi-cylindrical shell andcollars of FIG. 7 . FIG. 8A shows a detail view of constricting means ofthe collars. FIG. 8B shows a detail view of a recess of a ring segmentof the collar receiving a longitudinal rail of the shell.

FIG. 9 shows a perspective view of a cradle formed of a set of ringsegments resting on tank rollers.

FIG. 10 shows a perspective view of the cradle of FIG. 9 and apartly-assembled first semi-cylindrical shell. FIG. 10A shows a detailview illustrating formation of a tongue-and-groove joint of panelsassembled to form the first semi-cylindrical shell.

FIG. 11 shows a perspective view of the cradle and firstsemi-cylindrical shell of FIG. 10 with spacing disks resting upright inthe first semi-cylindrical shell.

FIG. 12 shows a perspective view of the cradle and firstsemi-cylindrical shell of FIG. 10 and spacing rings resting upright inthe first semi-cylindrical shell.

FIG. 13 shows a perspective view of the cradle, first semi-cylindricalshell, and spacing disks of FIG. 11 , with added flat extension panels,and a partly-assembled second semi-cylindrical shell.

FIG. 14 shows a perspective view of the cradle, quasi-cylindrical shell,spacing disks, and assembly of collars encompassing the shell.

FIG. 15 shows a perspective view of the collars and shell of FIG. 14with the spacing disks removed.

FIG. 16 shows an end view of the assembly of collars andquasi-cylindrical shell illustrating welding of inner joint seams androlling on tank rollers to bring the seams to a lower position, wherethe welding assembly has a single welding torch.

FIG. 17 shows an end view of the assembly of collars andquasi-cylindrical shell illustrating welding of inner joint seams androlling on tank rollers to bring the seams to a lower position, wherethe welding assembly has two welding torches.

FIG. 18 shows an end view of the quasi-cylindrical shell having weldedinner joint seams, with the collars removed, and illustrating welding ofouter joint seams and rolling on tank rollers to bring the outer jointseams to an upper position, where the welding assembly has a singlewelding torch.

FIG. 19 is a flowchart of a method of manufacturing a quasi-cylindricalcargo container.

Throughout the drawings, sometimes only one or fewer than all of theinstances of an element visible in the view are designated by a leadline and reference character, for the sake only of simplicity and toavoid clutter. It will be understood, however, that in such cases, inaccordance with the corresponding description, that all other instancesare likewise designated and encompassed by the correspondingdescription.

DESCRIPTION

A method of manufacturing a quasi-cylindrical cargo container, and anapparatus for performing the method, are disclosed herein.

While cylindrical cargo containers have many advantages, their availablevolumetric capacity, for a given length, is limited by their width,which is typically limited by regulation for travel on roads or rails.Conventional rectangular containers having the same width and height(i.e. having a square cross-section) have a greater volume than acylindrical container of the same length, by a factor of 4/π≈1.27.Moreover, rectangular containers typically have a greater height thanwidth, further increasing their volumetric capacity relative tocylindrical containers.

The inventors have discovered that all or many of the advantages ofcylindrical containers may be entirely or at least partly retained whileincreasing the volumetric capacity of the container, by providing acontainer formed from a plurality of curved longitudinal panels having acommon curvature, each of which has the shape of a cylinder segment, andthus when assembled would form a cylindrical tube, and additionally atleast two flat longitudinal extension panels. A first semi-cylindricalshell is formed from a first set of the curved longitudinal panels, atleast one flat longitudinal extension panel is provided at each of thelaterally opposing edges of the first semi-cylindrical shell, and asecond semi-cylindrical shell is formed from a second set of the curvedlongitudinal panels atop the flat longitudinal extension panels.

The resulting container has an oblong transverse vertical cross-section,with a shape which may be similar to the transverse verticalcross-section of a household heating oil tank. This shape may beunderstood to be the superimposition of a ‘U’ with an inverted ‘U’.Hereinafter, such planar shape will be designated as a “double-U shape”,or “extended circle”, or “vertically extended circle”, or“quasi-circle”, and when projected along an orthogonal axis theresulting hollow solid will be designated an “extended cylindricalshell”, or “extended cylinder”, or “vertically extended cylinder”, or“quasi-cylinder”, or similar terms, wherein it is understood that ahollow structure is intended. Related adjectives (e.g.“quasi-cylindrical”) are to be understood accordingly. As such,“extended” in this context is to be understood as connoting “verticallyextended”.

FIGS. 1 to 3 show a quasi-cylindrical cargo trailer 100. The trailer 100has a container 110 mounted on and supported by a wheeled suspension120. The container 110 has a generally vertically extended cylindricalshape, having a corresponding length t along a longitudinal axis L ofthe container (shown in FIG. 2 ), and a generally circular double-Ucross-section characterized by a vertical height h along a vertical axisV orthogonal to the longitudinal axis L and a traverse width w along atransverse axis T orthogonal to both of the longitudinal axis L andvertical axis V (shown in FIG. 3 ). Top and bottom portions of thecross-section consist of top and bottom halves of a circle, having adiameter 2 r equal to the transverse width w. The container 110 has afront end 130 and an rear end 140 oppositely disposed along thelongitudinal axis L of the container 110, and these may be configured inany desired manner, which may depend at least in part on an intendedfunction of the trailer.

The container 110 may have a tailgate 147 also having the double-Ushape, and thus sized and shaped for closing the rear opening 143. Thetailgate 147 may be movably mounted at or adjacent a perimeter of theopening 143 in any convenient manner. For example, the tailgate 147 maybe hingedly mounted, at or adjacent an edge of the tailgate 147, at oradjacent an upper edge of the opening 143, such that the tailgate 147 isopenable by rotating the tailgate 147 upwardly using the hinges 148, andcloseable by the opposite motion. Alternatively, the tailgate 147 may behingedly mounted, at or adjacent an edge of the tailgate 147, at oradjacent a lateral edge, such as a right edge or left edge, of theopening 143 such that the tailgate 147 is openable by rotating thetailgate 147 laterally, that is to one side, using the hinges, andcloseable by the opposite motion. The container 110 may include anappropriate locking mechanism selectively to maintain the tailgate 147in a locked configuration or to permit the tailgate 147 to open. In thisway, the tailgate 147 may be closed to retain cargo in the container110, and opened to permit loading or discharge of cargo to or from thecontainer 110

The upper and lower semi-cylindrical portions of the container 110 maybe formed of longitudinal curved panels 151, and the vertical portionsof the container 110 bridging the upper and lower semi-cylindricalportions may be formed of at least one longitudinal flat extension panel152 at each side of the container 110. The curved panels 151 may beformed of a continuous thickness of resilient plate material and shaped,which may be by bending, extrusion, rolling, or any other suitabletechnique, to provide the longitudinal curved panels 151 with a commoncurvature. The vertical extension panels 152 may be formed of acontinuous thickness of resilient plate material and shaped, which maybe by bending, extrusion, rolling, or any other suitable technique. Thepanels 150 (encompassing both the curved panels 151 and flat panels 152)may be formed of any suitable material, which may be a metal, which maybe steel or aluminum, and have any suitable dimensions includingthickness. The following are non-limited examples. In some embodiments,the panels 150 have a thickness of between 0.5″ and 6″ (1.27 cm and15.24 cm), or between 1″ and 4″ (2.54 cm and 10.16 cm), or about 1.5″(3.81 cm).

Other materials and manufacturing techniques are possible, and theprinciples disclosed herein are not necessarily limited to anyparticular materials or manufacturing techniques to produce the panels.For example, the principles disclosed herein may be applicable where thepanels are formed of non-metals including plastics, for examplethermoplastics, including for example high density polyethylene, orfiberglass. So long as the panels are sufficiently rigid and strong inview of the principles disclosed herein, any and all differentmaterials, dimensions, and manufacturing techniques are possible.

In order to form, when assembled, the quasi-cylindrical tube of thecontainer 110 having a double-U cross-section, as shown particularly inFIG. 3 , each curved panel 151 may have a cross-section generallyarcuate in shape, which for all of the curved panels 151 may have acommon arc radius r, or degree of curvature. Thus, each curved panel 151may form a cylinder segment, meaning a portion of a cylinder bounded bya secant plane parallel to the longitudinal axis of the cylinder, suchthat, if assembled, the curved panels 151 together would form acylindrical shell, meaning a 3D annulus, being a projection of a 2Dannulus along the axis of rotational symmetry of the 3D annulus—or, inother words, a hollow cylinder, or tube. The curved panels 151 may allhave the same arc length s, or some of the panels curved 151 may have adifferent arc length s from other ones of the curved panels 151. Anysuitable combination is possible. The following are non-limitingexamples. In some embodiments, the curved panels 151 have an arc radiusr of between 2.5′ and 6′ (0.762 m and 1.8288 m), or between 3.5′ and 5′(1.0668 m and 1.524 m), or about 51″ (1.2954 m). In some embodiments,the curved panels 151 have an arc length s of between 10″ and 32″ (25.4cm and 81.28 cm), or between 18″ and 26″ (45.72 cm and 66.04 cm), orabout 22″ (55.88 cm).

As shown particularly in FIG. 3A, each panel 150 may be formed with atongue 158 at a first edge at one end of the arc and a groove 159 at anopposite edge at an opposite end of the arc. The tongues 158 and grooves159 of the different panels 150 may be configured with respective sizesand shapes to couple fittingly. In this way, a plurality of the panels150 may be joined at abutting edges by mating the tongue 158 of onepanel 150 with the groove 159 of an abutting panel 150 to form a joint160, and as shown particularly in FIG. 3 multiple panels may be sojoined in sequence to form the quasi-cylindrical tube. Each of thejoints 160 so formed may be cemented or affixed by any suitable means,which may include fasteners or welds. Other mating means or techniquesare possible. For example, instead of a tongue-and-groove arrangement,the edge of one adjacent panel may be rounded with a preconfiguredconvex curvature, and the edge of the mating adjacent panel may berounded with a preconfigured concave curvature matching the convexcurvature, such that the first convex rounded edge abuts fittingly thesecond concave rounded edge. Other suitable mating arrangements may beused.

The panels 150 may be of any desired length, which may include a lengthwhich bridges the front end 130 and the rear end 140 of the container110—in other words, the entire length l of the container 110. All of thepanels 150 may have the same length, or first ones of the panels 150 mayhave a first length different from a second length of second ones of thepanels 150. Further combinations are possible. The following arenon-limiting examples. In some embodiments, the panels 150 have a lengthof between 20′ and 100′ (6.096 m and 30.48 m), or between 40′ and 80′(12.192 m and 24.384 m), or between 50′ and 60′ (15.24 m and 18.288 m),or about 56′ (17.0688 m), or about 53′ (16.1544 m).

As shown particularly in FIG. 3 , some of the panels 150 may includepanels 153 formed with a profile including one or more projectionsconfigured for selected purposes. For example, and as shown in FIG. 3one or more, which may be two, of the panels 153 may be formed withlongitudinal rails 170 or flanges to be coupled to a chassis 122 of thewheeled suspension 120 (shown in FIG. 1 ), for example by fasteners orwelds, for mounting the container 110 to the wheeled suspension 120. Insuch case, the profiles, include the two profiles, may be configured insuch a way that the mounting rails 170 or flanges are positioned andshaped in such a way that is generally symmetrical relative to avertical plane longitudinally bisecting the container 110, as shownparticularly in FIG. 3 . Such mounting rails 170 may also be configured,sized, and shaped to provide structural strength to the container 110.Other projections may instead or also be included in the extrusionprofile of one or more panels 150 for any desired purpose, for examplefor attachment of landing gear 124 or a fifth wheel, or hitch 126.

In order to provide the quasi-cylindrical container 110 having avertical transverse cross-section with the double-U shape, at least oneflat longitudinal vertical extension panel 152 is provided at eachtransverse opposite side of the container 110 and sandwiched between thelongitudinal curved panels 151 forming the uppermost panel 154 of afirst, lower semi-cylindrical shell 410, and the bottommost panel 155 ofa second, upper semi-cylindrical shell 420. On each side, the one ormore flat panels 152 may have a common total vertical dimension, orwidth w_(ext). The width w of the container is related to the radius ofcurvature r of the curved panels 151 which together form the firstsemi-cylindrical shell 410 and second semi-cylindrical shell 420,specifically by w=2r. Since the first semi-cylindrical shell 410 andsecond semi-cylindrical shell 420 absent the flat panels 152 would forma cylindrical shell, the height thereof would equal its width. As such,the total height h of the quasi-cylindrical container 110 ish=w+w_(ext). In other words, although the width w=2r of the container110 may be limited, which may be the result of governmental regulation,the height h may be variable by selection of the common total verticalwidth w_(ext) of the one or more flat longitudinal panels 152 to providethe desired total height h. Likewise, the volumetric capacity isvariable by selection of the common total vertical width w_(ext) of theone or more flat longitudinal panels 152, and equates tolr(πr+2w_(ext)). In some embodiments, the panels 152 have a common totalvertical dimension, or width w_(ext), of between 10″ and 32″ (25.4 cmand 81.28 cm), or between 18″ and 26″ (45.72 cm and 66.04 cm), or about22″ (55.88 cm). Other dimensions are possible.

As noted above, the panels 150, including the curved panels 151 and flatextension panels 152, which form the quasi-cylindrical container 110,may be formed of any suitable materials and by any suitablemanufacturing process. Further advantages may be obtained by forming thepanels 150 as longitudinal extruded panels formed of any suitablematerial, which may be a metal, which may be steel or aluminum.

Accordingly, FIGS. 4-6 show a quasi-cylindrical cargo trailer 100* whichis a particular instance, or embodiment, of the vertically extendedcylindrical cargo trailer 100, wherein the longitudinal panels 150*which form the container 110* are longitudinal extruded panels.(Reference characters having an asterisk (“*”) denote a specificembodiment of the more general element associated with the samereference character lacking the asterisk. Thus, container 110* is aspecific embodiment of container 110, longitudinal panels 150* are aspecific embodiment of longitudinal panels 150, and so on. In each case,the specific embodiment possesses all of the described characteristicsof the general element.)

As shown particularly in FIGS. 6A to 6C, each longitudinal extrudedpanel 150* may have an outer skin 252, an inner skin 254, and aplurality of webs 256 spanning the outer skin 252 and the inner skin254. The panels 150* may be formed of any suitable material, which maybe a metal, which may be steel or aluminum. The outer skin 252, theinner skin 254, and the webs 256 may have any respective dimensions. Thefollowing are non-limiting examples. The outer skin 252 may have athickness of at least 1 mm, or from 1 mm to 4 mm, or from 2 mm to 3 mm,or about 2.5 mm. The inner skin 254 may have a thickness of at least 2mm, or from 2 mm to 5 mm, or from 3 mm to 4 mm, or about 3.5 mm. Thewebs 256 may each have a thickness of at least 1 mm, or from 1 mm to 4mm, or from 2 mm to 3 mm, or about 2.5 mm. The outer skin 252 and theinner skin 254 may be spaced by a gap of at least 30 mm, or from 30 mmto 45 mm, or from 35 mm to 40 mm, or about 38 mm. The webs 256 may beprovided in any desired number, which may be at least 6, or 6 to 12, or8 to 10, or about 9. The webs 256 may be spaced by a gap or at least 15mm, or 15 mm to 35 mm, or 20 mm to 30 mm, or about 25 mm. Otherconfigurations are possible.

In order to form, when assembled, the cylindrical tube of the container110* having a vertically extended circular cross-section, as shownparticularly in FIG. 6 , each curved panel 151* may be extruded having across-section generally arcuate in shape, as shown particularly in FIG.6 , which for all of the panels 151* may have a common arc radius r*, ordegree of curvature. The panels 151* may all have the same arc lengths*, as shown in FIG. 6 , or some of the panels 151* may have a differentarc length s* from other ones of the panels. Any suitable combination ispossible. Each flat extension panel 152* may be extruded with agenerally flat profile, with a cross-section having a generallyrectilinear shape.

As shown particularly in FIGS. 6A-6C, each panel 150* may be extrudedwith a tongue 158* at a first edge at one end of the arc and a groove159* at an opposite edge at an opposite end of the panel 150*. Thetongues 158* and grooves 159* of the different panels 150* may beconfigured with respective sizes and shapes to couple fittingly. In thisway, a plurality of the panels 150* may be joined at abutting edges bymating the tongue 158* of one panel 150* with the groove 159* of anabutting panel 150* to form a joint 160*, and as shown particularly inFIG. 6 multiple panels 150* may be so joined in sequence to form thequasi-cylindrical, double-U shaped tube.

Where the panel 153* has a mounting rail 170*, the outer skin 252, theinner skin 254, and/or one or more of the webs 256 of the panel 153* maybe respectively formed with a greater thickness to provide additionalstrength and rigidity at or about the portion of the panel 153*adjoining the rail 170*, so as better to communicate the weight of thecontainer 110* and its contents to the rail 170* and thence to thewheeled suspension 120*. The panel 153* may be formed with its outerskin 252, inner skin 254, and/or webs 256 having respective thicknesseswhich are uniformly greater relative to the corresponding thicknesses ofother ones of the panels 150* not having the rail 170*. Alternatively,the panel 153* may be formed such that the respective thicknesses of itsouter skin 252 and/or inner skin 254 are generally similar to those ofneighbouring panels 150* where the panel 153* adjoins neighbouringpanels 150*, i.e. at or about its tongue 158* and groove 159*, but wherethe respective thicknesses of its outer skin 252 and/or inner skin 254grow approaching the portion of the panel 153* which is adjacent toand/or adjoins the rail 170*. Similarly, the webs 256 of the panel 153*in the portion of the panel 153* which is adjacent to and/or adjoins therail 170* may have a thickness which is relatively greater than athickness of the remaining webs 256 of the panel 153*, where thethickness of such remaining webs may be substantially similar to thewebs 256 of the other panels 150* not having the rail 170*. As with theouter skin 252 and the inner skin 254 of the panel 153*, the webs 256may grow in thickness approaching the portion of the panel 153* which isadjacent to and/or adjoins the rail 170*.

The longitudinal panels 150 so provided, assembled, joined, and affixed,to form the quasi-cylindrical tube of the container 110, may beconfigured to function as structural members, and provide each panel150, and the assembled container 110 as a whole, with structuralstrength and rigidity both along and transverse the longitudinal axis Lof the container. As such, no further reinforcing means may be required,such as annular bands or ribs required by conventional cylindricalcontainers.

Moreover, due to the lack of any need for such additional structuralmembers, both the inside and the outside surfaces of the container 110may be made completely smooth, without projections or with minimalprojections. With respect to the outside surface of the container 110,this provides the container with an optimal aerodynamic profile. Withrespect to the inside surface of the container 110, this completely ormaximally reduces the catching, or snagging, or other such impediment tomovement of the cargo within the container 110 along the inside surface,thereby facilitating loading and unloading of cargo from the container110.

Depending upon the intended use of the container 110, the particularconfiguration of the panels provides yet further advantages.

For example, when the trailer 100 is configured as a tanker trailer forliquefied loads, dry bulk cargo, or gases, the outside skin 252 of thepanels 150* may provide protection against impact or puncture from acollision or other blow coming from outside of the container 110*. Insuch case, the blow may cause a rupture in the outer skin 252 of a panel150*, but nevertheless the inner skin 254 may remain intact and itsstructural integrity unaffected or minimally affected by the presence ofthe rupture in the outer skin 252.

A similar advantage may be realized when the trailer 100* is configuredfor the transport of waste, such as municipal or industrial garbage. Oneissue related to the transport of such waste is that it typically exudesleachate, being liquid which has passed through or about the solid wasteand which has extracted soluble or suspended solids. It is desirable toavoid the release of leachate in an uncontrolled manner, as it isregarded to be an environmental hazard. It is desirable, therefore, toensure that it is not released during transport. Municipal or industrialwaste typically includes hard objects, however, which may puncture asurface of a container upon impact. In such case, the presentquasi-cylindrical container 110*, by virtue of the panels 150* havingboth an inner skin 254 and an outer skin 252, may provide a means ofprevention of discharge of leachate, inasmuch as the release of anyleachate following puncture of the inner skin 254, for example by impactwith hard objects contained in the waste, may be contained by the outerskin 252. Moreover, the webs 256 of the panel 150* may provide one ormore channels 290 which limit movement of the leachate.

As noted above, the above-described quasi-cylindrical cargo container110 possesses numerous advantages over previous cylindrical cargocontainers. There is further material value in an efficient and reliablemethod 300 of manufacturing such a cylindrical cargo container 110, asshown in FIGS. 7-19 .

The method 300 includes providing a plurality of rigid panels 150together formable into a vertically-extended quasi-cylindrical shell 405(step 305). A first semi-cylindrical shell 410 is formed from panels 415of a first set of curved panels 151 (step 310), one or more flatextension panels 152 are provided for each transverse side of the shell405 (step 312), a second semi-cylindrical shell 420 is formed frompanels 425 of a second set of the curved panels 151 (step 315), and thevertically extended cylindrical shell 405 is assembled from the firstsemi-cylindrical shell 410, the flat extension panels 152, and thesecond semi-cylindrical shell 420 (step 320). One or more collars 430are formed which conformably encompass the quasi-cylindrical shell 405(step 325). The collars 430 are constricted to compress joints 160formed at abutting edges of pairs of adjacent panels 150 (step 330). Thequasi-cylindrical shell 405 and collars 430 are then rolled about thelongitudinal axis of the shell 405 to bring respective joints 160 ofpairs of panels 150 to a lower position 440, and an inside seam 445 ofthe joint 160 is welded when at the lower position 440 to form a weldedinside seam 446 (step 335). The collars 430 are removed (step 340), andthe shell 405 is rolled about the transverse plane of the shell 405 tobring respective joints 160 of pairs of panels 150 to an upper position450, and an outside seam 455 of the joint 160 is welded when at theupper position 450 to form a welded outside seam 456 (step 345).

The shell 405 may constitute container 110, which may possess furtherelements beyond the shell 405 alone. A plurality of pairs of ringsegments 460 may be formable into collars 430 sized and shapedconformably to encompass the shell 405, as best seen in FIGS. 7 & 8 .Herein, “ring” connotes the shape of an annulus and “ring segment”connotes half of this shape, i.e. a semi-annulus. An alignment guide 509may be provided at each pair of facing ends of the ring segments whichtogether form a collar 430, and may be provided at either ring segment460 extending vertically from an outer edge of the ring segment 460. Thefunction of the alignment guide 509 is described below. An insidesurface of the cylindrical shell 405 and an outside surface of the ringsegments 460 may have, or be characterized by, a common curvature r,such that the collars 430 fittingly encompass the shell 405 at the firstsemi-cylindrical shell 410 and the second semi-cylindrical shell 420.Each of the ring segments may be formed of any suitable material ofsufficient durability, rigidity, and strength, including in someembodiments steel or stainless steel.

As best seen in FIG. 9 , a first set of the ring segments 460 may bering segments 465 which form a cradle 470, wherein the ring segments 465are longitudinally spaced and aligned concentrically to form asemi-cylindrical frame conformable to the first semi-cylindrical shell410. By “aligned concentrically”, it is meant that the respectivecircular axes of rotation of the ring segments 465, being the circularaxis of symmetry of the annulus of which the ring segment 465 is a part,are generally aligned, which may include being coincident. By“longitudinally spaced”, it is meant that the ring segments 465 arespaced along a longitudinal axis, which may include that coincidentcircular axis of rotation. The longitudinal spacing of the ring segments465 may be uniform, or irregular. The cradle 470 may further include oneor more longitudinal frame members 471, and the ring segments 465 may berigidly mounted on the frame members 471 to space the ring segments 465longitudinally and align them concentrically.

As best seen in FIG. 10 , the first semi-cylindrical shell 410 may beformed from curved panels 151 by laying the panels 151, which may beone-by-one in sequence, in the cradle 470 to form the firstsemi-cylindrical shell 410. The cradle 470 supports the panels 151 thusassembled to maintain the semi-cylindrical shape of the firstsemi-cylindrical shell 410. As shown in FIG. 10A, laying the panels 151in the cradle 470 to form the first semi-cylindrical shell 410 mayinclude joining the panels 151 at abutting edges by mating the tongue158 of one panel 151 with the groove 159 of an abutting panel 151 toform a joint 160, and joining the multiple panels 151 in sequence toform the first semi-cylindrical shell 410.

As noted above, one or more of the panels 151 may be panels 153 formedwith a profile or projection, which may be a longitudinal rail 170. Insuch case, the ring segments 465 which form the cradle 470 may be formedwith one or more recesses 472 sized, shaped, and positioned so asfittingly to receive the longitudinal rail 170 when the panel 153 islaid in the cradle 470, as best seen in FIGS. 8, 8B and 10 . Therecesses 472 may be sized and shaped such that an inside surface 473 ofthe recess 472 fittingly contacts an outside surface 458 of thelongitudinal rail 170, or they may be sized and shaped to provide a gapbetween the inside surface 473 of the recess 472 and the outside surface458 of the longitudinal rail 170. In this way, although the firstsemi-cylindrical shell 410 including panels 153 having longitudinalrails 170 would not have an external surface that is an unbrokensemi-cylinder, the ring segments 465 with recesses 472 provide outerradial surfaces 467 that are smooth, unbroken semi-annuli. Theusefulness of this feature will become apparent below.

Having formed the first semi-cylindrical shell 410 in the cradle 470, atleast one spacer 480 may be placed in the first semi-cylindrical shell410, which may be upright in the first semi-cylindrical shell 410. Aswill be seen below, the spacer is sized, shaped, and configured to spaceat least some of the panels 150 to maintain a quasi-cylindrical shape ofthe shell 405, once assembled.

For example, as shown in FIG. 11 , the at least on spacer 480 mayinclude at least one vertical extended quasi-circular, double-U shapedspacing disk 481, which may be placed upright in the firstsemi-cylindrical shell 410 so as to contact respective inside surfacesof at least some of the panels 151 of the first semi-cylindrical shell410. In this way, the first semi-cylindrical shell 410 may support theat least one spacing disk 481. The at least one spacing disk 481 mayinclude a plurality of rigidly assembled parts, which may include afirst semi-disk 482, a second semi-disk 483, and a rectangular plate 479configured for rigid assembly to form the double-U shaped spacing disk481. For this purpose, the first semi-disk 482, second semi-disk 483,and rectangular plate 479 may include any suitable fastening means (notshown) configured reversibly, but rigidly, to assemble the firstsemi-disk 482, the second semi-disk 483, and the rectangular plate 479to form the double-U shaped spacing disk 481. For example, the firstsemi-disk 482, second semi-disk 483, and rectangular plate 479 may eachhave one or more cooperating through holes (not shown) sized and spaceto receive cooperating bolts, such that when the through holes arealigned, bolts are passed therethrough, and affixed using cooperatingnuts, the first semi-disk 482 and rectangular plate 479, on the onehand, and also the rectangular plate 479 and second semi-disk 483, onthe other hand, are respectively rigidly, but reversibly, assembled intothe double-U shaped spacing disk 481. The spacing disk 481 may beprovided with one or more openings 484, which may be circular, and/orone or more scallops 485, which may be semi-circular, along a peripherythereof. The spacing disk 481 may be formed of any suitable material,and in some embodiments is formed of a metal which may include steel oraluminum.

Alternatively, as shown in FIG. 12 , the spacer 480 may include at leastone quasi-circular, double-U shaped spacing ring 486 comprising adouble-U shaped rim 487 formed with an outer U-shaped channel sized andshaped fittingly to receive an inflatable tube 488. The rim 487 may beformed of any suitable material, and in some embodiments is formed of ametal, which may include aluminum or steel. The inflatable tube 488 maybe formed of any suitable material, and in some embodiments is formed ofrubber or plastic. The inflatable tube 488 may comprise any connectionmeans 489 suitable to connect the inflatable tube 488 to a pressuresource (not shown), such as a hydraulic or pneumatic pump, operable topressurize the inflatable tube 488 and thereby to expand an outerperiphery of the inflatable tube 488. The rim 487 may include one ormore through holes 490 to allow passage of a portion 491 of the tube 488to facilitate connection of the connection means 489 to a hose 492 orother connection to the pressure source. As shown in FIG. 12 , in someembodiments the portion 491 of the tube 488 traverses through holes 490,and is a segment of the tube 488. In other embodiments, the portion 491is a radial segment cemented or welded onto the tube 488, and may besimilar to an inflation stem of a bicycle tube.

As shown in FIG. 13 , having placed the at least one spacer 480 in thefirst semi-cylindrical shell 410, the double-U shaped shell 405 may befully assembled. The one or more longitudinal flat extension panels 152may be laid atop the first semi-cylindrical shell 410 at eachtransversely opposite longitudinal edge thereof. It will be appreciatedthat the step of laying the vertical extension panels 152 atop the firstsemi-cylindrical shell 410 may alternatively be performed prior toplacement of the at least one spacer 480 in the first semi-cylindricalshell 410. In either case, the second semi-cylindrical shell 420 maythen be formed from curved panels 151 in substantially the same way asthe first semi-cylindrical shell 410, except instead of laying thepanels 151 in the cradle 470, the panels 151 may be laid atop thelongitudinal flat extension panels 152 and the at least one spacer 480to form the second semi-cylindrical shell 420. The at least one spacer480 may contact respective inside surfaces of at least some of thepanels 151 of the second semi-cylindrical shell 420, and thereby supportthe second semi-cylindrical shell 420 while maintaining asemi-cylindrical shape of the second semi-cylindrical shell 420. Layingthe panels 151 as described above to form the second-semi-cylindricalshell may include joining the panels 151 at abutting edges by mating thetongue 158 of one panel 151 with the groove 159 of an abutting panel 151to form a joint 160, and joining the multiple panels 151 in sequence. Inthis way, the quasi-cylindrical shell 405 may be formed from the firstsemi-cylindrical shell 410, the flat extension panels 152, and thesecond semi-cylindrical shell 420. The at least one spacer 480 may spacethe panels 150 to maintain the quasi-cylindrical, double-U shape of theshell 405.

Importantly, the shell 405 may be thus assembled without requiring anytack welding. It is common in the art of welding to position items to bewelded together and then form tack, or spot, welds as a temporary meansto hold the components in the desired positions until final welding canbe performed. In some embodiments, the panels 150 are free, orsubstantially free, of tack welds prior to creation of final weldsjoining adjacent panels. The above-described method including use of thecradle 470 and the at least one spacer 480 enables assembly of thequasi-cylindrical shell 405 without need for tack welds to maintain thedesired positions of the panels 150. Further advantages of the absenceof tack welds are discussed below.

Alternatively, in some embodiments tack welds may be used to dispensewith the at least one spacer 480. For example, following assembly of thefirst semi-cylindrical shell 410 as described above, the curved panels151 may be partly fastened, which may be by partial welding, which maybe by tack welding, at seams of the joints 160 of the panels 151,thereby to give the first semi-cylindrical shell 410 a preconfiguredpartial rigidity. Then, the first semi-cylindrical shell 410 may beremoved from the cradle 470, which may be by craning or any othersuitable conveyancing means, and the second semi-cylindrical shell 420may be formed in the cradle 470 in the manner described above withrespect to the first semi-cylindrical shell 410. Then, the longitudinalflat extension panels 152 may be laid at the transversely oppositelongitudinal edges of the second semi-cylindrical shell 420, and theseams of the joints 160 thus formed may be partly fastened, which may beby partial welding, which may be by tack welding, in order to providepartial rigidity between the vertical extension panels 152 and secondsemi-cylindrical shell 420. Then, the partly-affixed firstsemi-cylindrical shell 410 may be turned-over, or flipped, and placedatop the vertical extension panels 152, aligning the respectivelongitudinal edges, to form the quasi-cylindrical shell 405. Alternativemethods are also possible, and the principles disclosed herein areapplicable to any method where the shell 405 is formed from panels 150while maintaining the double-U shape of the shell 405.

Having formed the shell 405, a second set of the ring segments 460 maybe ring segments 500 respectively paired with ring segments 465 whichform the cradle 470, as shown particularly in FIG. 14 . As shownespecially in FIGS. 8, 8A and 14 , the ring segments 500 may be laidatop the shell 405 and the ring segments 465 in pairwise fashion so asto oppose respective adjacent ends 505 of each pair of ring segments 460(see FIG. 8A) to form the one or more collars 430 conformablyencompassing the shell 405. The pair of ring segments 460 form a gap 506at the opposing respective adjacent ends 505 when the collar 430 isformed. The gap 506 may be substantially equal to the common totalvertical dimension, or width w_(ext), of the one or more flat panels152, as described above. At each pair of opposing adjacent ends 505,either the lower ring segment 465 or the upper ring segment 500 may beprovided with an alignment guide 509 extending vertically from an outeredge of the ring segment 465, 500. The alignment guide 509 may beaffixed to the ring segment 465, 500, which may be by fasteners orwelds, and may function to urge, guide, or maintain the paired ringsegments 465, 500 into lateral, transverse alignment, or to resisttransverse misaligned of the pair of opposing adjacent ends 505.

The collar 430 may be provided with constricting means 510 where therespective adjacent ends 505 of the pair of ring segments 460 oppose.For example, the ring segments 460 may include through holes in flanges507 at the respective adjacent ends 505 of the pair of ring segments 460where they oppose, and a bolt 511 and nut 512 combination. By insertingthe bolt 511 into the through holes, threading the nut 512 onto the bolt511, and tightening the nut 512 in the known manner, the ends 505 may bedrawn together, reducing the gap 506, causing an inner surface of thecollar 430 to apply a substantially uniform force about the periphery ofthe shell 405. In this way, at least some of the pairs of panels 150 maybe compressed at their respective joints 160. One or more of the collars430 may be provided with substantially similar constricting means 510 ateach of the respective adjacent ends 505 where the pair of ring segments460 oppose, as shown in FIG. 8 . Alternatively, the pair of ringsegments 460 may be provided with a fixed attachment, for example ahinge, at one side, and constricting means 510 at the other side. Insome embodiments, the constricting means 510 may include one or more ofa ratchet, a cam lever, or a motor. Other configurations are possible toprovide the function of constricting the shell 405 in order to compressat least some of the pairs of panels 150 at their respective joints 160.

Having clamped and constricted the shell 405 in this way, it may becomeunnecessary to retain the spacers 480 in order to maintain thevertically extended cylindrical shape of the shell 405. The pressuredeveloped at the joints 160 may be sufficient to maintain the verticallyextended cylindrical, double-U shape of the shell 405. Accordingly, asshown in FIG. 15 , the spacers 480 (not shown in FIG. 15 , but shown inFIGS. 11 through 14 ) may be removed leaving the shell 405 with anunobstructed hollow. For example, where the spacers 480 include at leastone circular spacing disk 481, removal may include disassembling it intothe first semi-disk 482, rectangular plate 479, and second semi-disk483, for example by loosening of the nuts and removal of the bolts inthe aligned through holes which hold the first semi-disk 482,rectangular plate 479, and second semi-disk 483 together, followed byremoval of the first semi-disk 482, rectangular plate 479, and secondsemi-disk 483 from the interior of the shell 405. Where the spacers 480include at least one spacing ring 486, removal may include at leastpartial release of pressure from the inflatable tube 488 so as at leastpartially to deflate it thereby to reduce pressure between theinflatable tube 488 and the inside surface of the shell 405, followed byremoval of the spacing ring 486 from the interior of the shell 405.

As discussed above, the shell 405 may be formed free, or substantiallyfree, of tack welds or other adjoining alterations or fasteners prior tothe formation of final welds to join the panels 150. In such case, theadditional advantage may be achieved that the constriction of the shell405 using the collars 430 and constricting means 510 to compress atleast some of the pairs of panels 150 at their respective joints 160 maydo so more effectively or more optimally, as compared to when tack weldsare used, inasmuch as the panels 150, when free or substantially free oftack welds, are more free to move at the joints 160, and thus a morecompressed joint 160 may be achieved, thereby enabling a superior finalweld.

As shown in FIG. 16 , with the interior hollow of the shell 405unobstructed, the inside seams 445 of the joints 160 of respective pairsof panels 150 may be welded in a single welding operation to produce awelded inside seam 446.

As is known in the art, superior welds are usually formed when the heatsource is applied directly vertically above the seam to be welded, suchthat the weld pool formed by fusion of the materials at the joint restsin the seam and is not drawn, or is minimally drawn, by gravity awayfrom the joint. When the heat source is not directly vertically abovethe seam, but is displaced angularly from this position, and especiallyif it is directly vertically below the seam, then there may occur atleast some flow of the weld pool away from an optimal position in thejoint, and the quality of the weld may be reduced. Thus, it ispreferable to weld ‘downwardly’, that is with the heat source directlyvertically above the seam to be welded.

Thus, in order to produce a superior welded seam 446, the assembly ofthe shell 405 and collars 430 may be rolled, or rotated (illustrated byarrow 537) about the longitudinal axis L of the shell 405 (shown in FIG.2 ) to bring the joint 160 to a lower position 440, and the inside seam445 may be welded to produce the welded inside seam 446 when at thelower position 440. The lower position 440 may be substantially thelowermost point on the inner periphery of the shell 405, or in otherwords the lower position 440 may be plumb the longitudinal axis L.Alternatively, the lower position 440 may be angularly displaced fromthe lowermost point by a predetermined or limited amount. Withoutlimitation, the joint 160 may be angularly displaced from the lowermostpoint by less than about 90°, or less than about 70°, or less than about45°, or less than about 10°. Positioning of the inside seam 445 at thelower position 440 in this way which enables the production of a weldedinside seam 446 of superior strength and quality as compared to a weldedseam when the seam must be welded not downwardly, but instead upwardlyor at an intermediate angle.

In order to roll the assembly of the cylindrical shell 405 and thecollars 430, the assembly may be placed on a rolling apparatusconfigured to enable the above-described rolling of the assembly of theshell 405 and the collars 430. For example, the rolling apparatus mayinclude one or more, which may be at least a pair, of tank rollers 521including a base 522 and at least a pair of cylindrical rollers 523mounted on the base 522. As shown in FIGS. 8 to 18 , the rollers 523 ofthe may contact and support outer surfaces 467 of corresponding collars430. The tank rollers 521 may include one or more motors (not shown) todrive one or more of the rollers 523. The assembly of the shell 405 andthe collars 430 may be smoothly and easily rolled about the longitudinalaxis L using the tank rollers 521. Moreover, by supporting the collars430 with the rollers 523 of the tank rollers 521 as opposed to the outersurface of the shell 405, if the shell 405 includes one or more panels153 formed with a profile or projection, which may be longitudinal rails170, and the collars 430 include ring segments 460 formed withcorresponding recesses 472 (best shown in FIGS. 8, 8B, and 9 ), then theprojections impose no obstacle to the smooth and uninterrupted rollingof the assembly of the shell 405 and the collars 430 through one or morefull rotations about the longitudinal axis L.

The assembly of the shell 405 and the collars 430 may be placed on thetank rollers 521 after assembly, by using a crane or other conveyancingmeans, for example, or as shown in FIGS. 9-15 , the cradle 470 mayinitially be formed and positioned on the tank rollers 521 and theassembly of the shell 405 and the collars 430 may be assembled while thecradle 470 is supported by the tank rollers 521.

The inside seam 445 of each joint 160 may be welded by any suitablemeans. For example, each inside seam 445 may be welded manually by ahuman welder using a welding apparatus 530, and this may be facilitatedby the absence of any obstacle within the hollow of the shell 405. Thewelding apparatus 530 may include a handheld torch, or alternatively, asshown in FIG. 16 , may include a welding carriage 531 including awelding head 532 slidingly suspended from a suspension line 533supported at opposite ends by suspension line supports (not shown). Thewelding head 532 may be movable along the seam 445 by a human operator,or the welding carriage 531 may be movable automatically, and thus mayinclude robotic means, which may include robotic motion systems and/orrobotic vision systems. As shown in FIG. 16 , the welding head 532 mayinclude a single welding torch 534, or as shown in FIG. 17 it may havemore than one welding torch 534, which may be two welding torches 534.In the latter case, the welding apparatus 530 may be operable to weldtwo inside seams 445 at a time, per motion of the of the welding head532 from one end of the shell 405 to the other end, and for each pair ofseams 445 the shell 405 may be rolled either to position one of the twoseams 445 at the lowermost position 440, or instead to position amidpoint between the two seams 445 at the lowermost position 440 so asto minimize a displacement of each seam from the lowermost position 440.

The form and nature of the welding apparatus 530, including the weldinghead 532 and welding torch 534, may depend on the material of the panels150, and in general will be selected according to the material of thepanels 150. For example, when the panels 150 are formed of aluminum, thewelding apparatus 530 may include any suitable welding technology,appropriate for the material to be welded, and in some embodimentsincludes steel or aluminum welding technologies, which may includeconstant voltage, constant current, pulsed welding, or laser weldingtechnology.

As shown in FIG. 18 , once all of the inner seams 445 of the joints 160are welded to form welded inner seams 446, the outer seams 455 of thejoints 435 may be welded to form welded outer seams 456. The collars 430may be removed in order to expose the entire outer surface of the shell405, including the entire length of each outer seam 455 withoutobstacle. For example, the assembly of the shell 405 and collars 430 maybe lifted using a crane or other conveyancing means, the collars 430 maybe removed by unfastening the constricting means 510 and separating andremoving the ring segments 460, and the shell 405 may be replaced on thetank rollers 521. The welded inner seams 446 may provide sufficientstructural strength to the shell 405 that substantially no movement, orminimal movement, or movement within preconfigured tolerances, occurs ofthe panels 150 relative to one another during movement of the shell 405.

When the rolling apparatus 520 includes the tank rollers 521, as shownin FIG. 18 , the shell 405 may be rolled, or rotated, about itslongitudinal axis L to bring each outer seam 455 in turn to an upperposition 540, which may be substantially the uppermost point on theouter periphery of the shell 405. Each outer seam 455 may be welded toform a welded outer seam 456 in substantially the same way as the innerseams 445 are welded to form the welded inner seams 446. Thus, as shownin FIG. 18 , a welding apparatus 550 may be provided and suspended abovethe shell 405 which is substantially similar to the welding apparatus530 used to weld the inner seams 445, and described above. As was thecase with the inner seams 445, positioning of the outer seam 455 at theupper position 540 and disposition of the welding apparatus 550 directlyabove the outer seam 455, thereby enabling vertically downward weldingof the outer seam 455, may enable the production of a welded outer seam456 of superior strength and quality as compared to a welded seam whenthe seam must be welded not downwardly, but instead upwardly or at anintermediate angle.

Providing both welded inner seams 446 and welded outer seams 456 mayprovide for a stronger and more water-tight weld, as compared toproviding only welded inner seams 446 or only welded outer seams 456. Insome embodiments, however, it may be sufficient to provide only weldedinner seams 446 or only welded outer seams 456, and yet provide a weldedshell with sufficient strength, integrity, and/or water-tightness, forthe particular application of the embodiment. In such case, manufactureof the shell 405 may be simplified.

The techniques described above may provide numerous advantages. Forexample, by enabling the welding of seams in an optimal, downwardposition, the cylindrical shell may be provided with improved, oroptimal, or maximal structural strength and integrity. Moreover,formation of the cylindrical shell followed by constriction using thecollars and constricting means, thereby developing pressure at the paneljoints, may also improve the structural strength and integrity of thewelded seams. This may be true especially as compared to welded seamsformed if the panels are assembled only loosely, and not under suchpressure. The improvement in structural strength and integrity of thewelded seams, and thus the quasi-cylindrical shell, may be sufficient toreduce or eliminate the requirement for other structural elements, forexample ribs or internal and/or external flanges, in some embodiments.Moreover, the improved integrity of the welded seams may enable theproduction of a water-tight, or substantially water-tight, container.

Moreover, the use of the collars and rolling apparatus may reduce orminimize manufacturing time by reducing or minimizing the time requiredto bring each seam to an optimal vertically downward position forwelding. Moreover, the use of the spacers may enable the formation ofthe quasi-cylindrical shell under pressure thereby enabling many of theadvantages described above. Finally, the techniques described herein mayreduce, and may reduce substantially, the time and effort required toconstruct quasi-cylindrical trailers from longitudinal panels.

The quasi-cylindrical shell manufactured as described herein may formand be used to construct a quasi-cylindrical cargo container, includinga quasi-cylindrical cargo container for a tanker truck, or a trailer, ora railcar, which in turn may be used to construct a tanker truck, atrailer, or a railcar respectively, by assembly with any desiredadditional components, as discussed hereinabove and as known in the art.

The following are examples according to the disclosure herein.

Example 1. A quasi-cylindrical cargo container comprising a plurality ofpanels, the panels comprising a plurality of curved panels having acommon curved shape characterized by a curvature and a plurality of flatextension panels, wherein adjacent pairs of the panels are joined atrespective abutting edges, and the joined panels form aquasi-cylindrical tube.

Example 2. The quasi-cylindrical cargo container according to Example 1,wherein the curved panels are extruded curved panels, and for at leastone of the extruded curved panels an extrusion axis of the extrudedcurved panel is parallel to a longitudinal axis of the quasi-cylindricaltube, and a cross-sectional profile of the extruded curved panelperpendicular to the extrusion axis has the curved shape.

Example 3. The quasi-cylindrical cargo container according to Example 1,wherein the curved panels are extruded curved panels and for each one ofthe extruded curved panels an extrusion axis of the extruded curvedpanel is parallel to a longitudinal axis of the quasi-cylindrical tube,and a cross-sectional of the extruded curved panel perpendicular to theextrusion axis has the curved shape.

Example 4. The quasi-cylindrical cargo container according to Example 3,wherein each extruded curved panel is formed by extrusion with anextrusion profile being the cross-section having the curved shape.

Example 5. The quasi-cylindrical cargo container according to Example 3,wherein each curved panel is formed by bending to provide the curvedpanel having the cross-section having the curved shape.

Example 6. The quasi-cylindrical cargo container according to any one ofExamples 1 to 5, wherein the curved shape of each of the curved panelshas a common arc length.

Example 7. The quasi-cylindrical cargo container according to any one of

Examples 1 to 5, wherein the curved shape of at least a first one of thecurved panels has a first arc length different from a second arc lengthof the curved shape of at least a second one of the curved panels.

Example 8. The quasi-cylindrical cargo container according to any one ofExamples 1 to 7, wherein each one of the panels has a commonlongitudinal length.

Example 9. The quasi-cylindrical cargo container according to any one ofExamples 1 to 7, wherein at least a first one of the panels has a firstlongitudinal length different from a second longitudinal length of atleast a second one of the panels.

Example 10. The quasi-cylindrical cargo container according to any oneof Examples 1 to 9, wherein at least one of the panels comprises aprojection configured for coupling to a support.

Example 11. The quasi-cylindrical cargo container according to Example10, wherein the projection comprises a rail integral with and extendingalong a length of the at least one panel and configured for mounting tothe support.

Example 12. The quasi-cylindrical cargo container according to any oneof Examples 1 to 9, wherein each of two of the panels comprises aprojection configured for coupling to a support, the projectioncomprising a rail integral with and extending along at least a part of alength of the panel and configured for mounting to the support, whereinthe two panels are relatively positioned to form the quasi-cylindricaltube such that the corresponding rails are symmetrically positionedrelative to a transverse center of the container.

Example 13. The quasi-cylindrical cargo container according to any oneof Examples 10 to 12, wherein the support comprises landing gear, afifth wheel, or a hitch.

Example 14. The quasi-cylindrical cargo container according to any oneof Examples 1 to 13, wherein the adjacent pairs of the panels are joinedat the respective abutting edges in a tongue-and-groove joint, wherein atongue provided at the abutting edge of one of the panels is mated in agroove provided at the abutting edge of the other one of the panels.

Example 15. The quasi-cylindrical cargo container according to any oneof Examples 1 to 14, wherein adjacent panels are joined at therespective abutting edges using fasteners or welds.

Example 16. The quasi-cylindrical cargo container according to any oneof Examples 1 to 15, wherein the panels are formed of aluminum.

Example 17. The quasi-cylindrical cargo container according to any oneof Examples 1 to 16, wherein each panel comprises an inner skin and anouter skin sandwiching a plurality of webs bridging a space between theinner skin and the outer skin.

Example 18. The quasi-cylindrical cargo container according to Example17, wherein the outer skin has a thickness of at least 1 mm, the innerskin has a thickness of at least 2 mm, the webs each have a thickness ofat least 1 mm, the outer skin and the inner skin are spaced by a gap ofat least 30 mm, and the webs are spaced by a gap of at least 15 mm.

Example 19. The quasi-cylindrical cargo container according to Example17, wherein the outer skin has a thickness of about 2.5 mm, the innerskin has a thickness of about 3.5 mm, the webs each have a thickness ofabout 2.5 mm, the outer skin and the inner skin are spaced by a gap ofabout 38 mm, and the webs are spaced by a gap of about 25 mm.

Example 20. The quasi-cylindrical cargo container according to Example17, wherein the outer skin has a thickness of from 2 mm to 3 mm, theinner skin has a thickness of from 3 mm to 4 mm, the webs each have athickness of from 2 mm to 3 mm, the outer skin and the inner skin arespaced by a gap of from 35 mm to 40 mm, and the webs are spaced by a gapof from 20 mm to 30 mm.

Example 21. The quasi-cylindrical cargo container according to any oneof Examples 17 to 23, wherein for at least one of the panels, the outerskin, the inner skin, and the webs form a channel.

Example 22. The quasi-cylindrical cargo container according to any oneof Examples 1 to 21 having a front wall and an end wall enclosing thecontainer.

Example 23. The quasi-cylindrical cargo container according to any oneof Examples 1 to 21 having a front wall and a rear opening for passageof the cargo, and a tailgate hingedly mounted at or adjacent a perimeterof the rear opening closeable to retain the cargo in the container andopenable to permit passage of the cargo through the rear opening.

Example 24. The quasi-cylindrical cargo container according to any oneof Examples 1 to 23 substantially free from reinforcing annular bands orribs.

Example 25. The quasi-cylindrical cargo container according to any oneof Examples 1 to 24, wherein an inside surface of the cylindrical cargocontainer is free from projections.

Example 26. The quasi-cylindrical cargo container according to any oneof Examples 1 to 25, wherein a transverse cross-section of thequasi-cylindrical tube has a shape substantially of a ‘U’ superimposedwith an inverted ‘U’.

Example 27. A quasi-cylindrical cargo container comprising: a firstsemi-cylindrical shell; a second semi-cylindrical shell; and a pluralityof flat extension panels bridging respective opposing longitudinal edgesof the first semi-cylindrical shell and the second semi-cylindricalshell.

Example 28. The quasi-cylindrical cargo container according to Example27 having a transverse cross-section in a shape of a ‘U’ superimposedwith an inverted ‘U’.

Example 29. The quasi-cylindrical cargo container according to Example27 or 28, comprising a first extension panel bridging a first pair ofopposing longitudinal edges of the first semi-cylindrical shell and thesecond semi-cylindrical shell, and a second extension panel bridging asecond pair of opposing longitudinal edges of the first semi-cylindricalshell and the second semi-cylindrical shell.

Example 30. The quasi-cylindrical cargo container according to Example29, wherein the first extension panel and the second extension panelhave a common width.

Example 31. The quasi-cylindrical cargo container according to Example27 or 28, comprising a first plurality of extension panels bridging afirst pair of opposing longitudinal edges of the first semi-cylindricalshell and the second semi-cylindrical shell, and a second extensionpanel bridging a second pair of opposing longitudinal edges of the firstsemi-cylindrical shell and the second semi-cylindrical shell.

Example 32. The quasi-cylindrical cargo container according to Example31, wherein the first plurality of extension panels together, and thesecond extension panel, have a common width.

Example 33. The quasi-cylindrical cargo container according to Example27 or 28, comprising a first plurality of extension panels bridging afirst pair of opposing longitudinal edges of the first semi-cylindricalshell and the second semi-cylindrical shell, and a second plurality ofextension panels bridging a second pair of opposing longitudinal edgesof the first semi-cylindrical shell and the second semi-cylindricalshell.

Example 34. The quasi-cylindrical cargo container according to Example33, wherein the first plurality of extension panels together, and thesecond plurality of extension panels together, have a common width.

Example 35. A trailer or truck comprising the quasi-cylindrical cargocontainer according to any one of Examples 1 to 34 mounted to a chassissupported by a wheeled suspension.

Example 36. A railcar comprising the quasi-cylindrical cargo containeraccording to any one of Examples 1 to 34 mounted to a chassis supportedby a wheeled suspension.

Example 37. A method of manufacturing a quasi-cylindrical cargocontainer, the method comprising: providing a plurality of longitudinalpanels comprising: rigid curved panels together formable into acylindrical shell, each curved panel comprising an oblong cylindersegment of the cylindrical shell; and two rigid, flat extension panelshaving a common width; providing a plurality of pairs of ring segments,each pair of ring segments sized and shaped to conformably encircle thecylindrical shell; providing a cradle comprising a first set of the ringsegments longitudinally spaced and aligned concentrically to form asemi-cylindrical frame conforming to the cylindrical shell; laying afirst set of the curved panels in the cradle so as to abut respectivelongitudinal edges of each pair of adjacent curved panels to form afirst semi-cylindrical shell; placing at least one spacer upright in thefirst semi-cylindrical shell so as to contact respective inside surfacesof at least some of the panels of the first semi-cylindrical shellwhereby the first semi-cylindrical shell supports the at least onespacer; laying the extension panels atop the first-semi-cylindricalshell so as to abut respective longitudinal edges of outermost curvedpanels of the first set of panels and longitudinal edges of adjacentextension panels; laying a second set of the panels atop the verticalextension panels and the at least one spacer so as to abut respectivelongitudinal edges of outermost curved panels of the second set ofpanels and adjacent extension panels to form a second semi-cylindricalshell atop the extension panels and the at least one spacer, wherein:the at least one spacer contacts respective inside surfaces of at leastsome of the panels of the second semi-cylindrical shell, supports thesecond semi-cylindrical shell, and maintains a cylindrical shape of thecylindrical shell; the abutting respective longitudinal edges of eachpair of adjacent panels forms a joint; and the first semi-cylindricalshell, the extension panels, and the second-semi-cylindrical shelltogether form a quasi-cylindrical shell; laying a second set of the ringsegments atop the quasi-cylindrical shell and above the first set ofring segments in pairwise fashion so as to oppose respective adjacentends of each pair of ring segments thereby forming the collarsconformably encompassing the quasi-cylindrical shell; clamping thequasi-cylindrical shell by constricting the collars using constrictingmeans provided at the opposing respective adjacent ends of each pair ofring segments, thereby compressing at least some of the pairs of thepanels at their respective joints; removing the at least one spacer,whereby a hollow of the quasi-cylindrical shell is unobstructed; using arolling apparatus to roll the quasi-cylindrical shell and collars abouta longitudinal axis of the quasi-cylindrical shell so as sequentially tobring the joint of each pair of panels to a lower position, and weldingan inside seam of the joint when at the lower position; removing thecollars from the quasi-cylindrical shell; and using the rollingapparatus to roll the quasi-cylindrical shell and collars about thelongitudinal axis of the quasi-cylindrical shell so as sequentially tobring the joint of each pair of panels to an upper position, and weldingan outside seam of the joint when at the upper position.

Example 38. A method of manufacturing a quasi-cylindrical cargocontainer, the method comprising: providing a plurality of longitudinalpanels formable into a quasi-cylindrical shell, the panels comprising:rigid curved panels together formable into a cylindrical shell, eachcurved panel comprising an oblong cylinder segment of the cylindricalshell; and at least two rigid, flat extension panels; providing aplurality of pairs of ring segments, each pair of ring segments beingsized and shaped to conformably encompass the quasi-cylindrical shell;providing a cradle formed from a first set of the ring segments; layinga first set of the curved panels in the cradle to form a firstsemi-cylindrical shell; placing at least one spacer in the firstsemi-cylindrical shell; laying the extension panels atop the firstsemi-cylindrical shell; laying a second set of the panels atop theextension panels and the at least one spacer to form a secondsemi-cylindrical shell, the first semi-cylindrical shell, the extensionpanels, and the second-semi-cylindrical shell together forming thequasi-cylindrical shell, the at least one spacer spacing the panels tomaintain a shape of the quasi-cylindrical shell; laying a second set ofthe ring segments atop the quasi-cylindrical shell and above the firstset of ring segments in pairwise fashion so as to form the collarsconformably encompassing the quasi-cylindrical shell; clamping thequasi-cylindrical shell by constricting the collars using constrictingmeans provided at each collar, thereby compressing joints formed atabutting respective edges of each pair of adjacent panels; removing theat least one spacer, whereby a hollow of the quasi-cylindrical shell isunobstructed; using a rolling apparatus to roll the quasi-cylindricalshell and collars about a longitudinal axis of the quasi-cylindricalshell so as sequentially to bring the joint of each pair of panels to alower position, and welding an inside seam of the joint when at thelower position; removing the collars from the quasi-cylindrical shell;using the rolling apparatus to roll the quasi-cylindrical shell about alongitudinal axis of the quasi-cylindrical shell so as sequentially tobring the joint of each pair of panels to an upper position, and weldingan outside of the joint when at the upper position.

Example 39. A method of manufacturing a quasi-cylindrical cargocontainer, the method comprising: providing a plurality of longitudinalpanels formable into a quasi-cylindrical shell having aquasi-cylindrical shape, the panels comprising: rigid curved panelsformable into a cylindrical shell, each curved comprising a cylindersegment of the cylindrical shell; and at least two rigid, flat extensionpanels; forming the quasi-cylindrical shell from the panels; forming atleast one collar conformably encompassing the quasi-cylindrical shell;constricting the at least one collar to compress longitudinal jointsformed at abutting edges of pairs of adjacent panels; and weldingrespective joints of pairs of the panels.

Example 40. The method according to Example 39, wherein welding therespective joints of pairs of the panels comprises: welding respectiveinside seams of the joints.

Example 41. The method according to Example 40, wherein welding therespective inside seams of the joints comprises: moving the respectivejoints of the pairs of panels to a lower position, and welding therespective inside seams of the joints when at the lower position.

Example 42. The method according to any one of Examples 39 to 41,wherein each curved panel comprises an oblong cylinder segment of thecylindrical shell.

Example 43. The method according to any one of Examples 39 to 42,wherein forming the quasi-cylindrical shell from the panels comprises:forming a first semi-cylindrical shell from a first set of the curvedpanels; forming a second semi-cylindrical shell from a second set of thecurved panels; and forming the quasi-cylindrical shell from the firstsemi-cylindrical shell, the extension panels, and the secondsemi-cylindrical shell.

Example 44. The method according to any one of Examples 39 to 43,wherein each of the at least one collar comprises a pair of ringsegments formable into the collar sized and shaped conformably toencompass the quasi-cylindrical shell.

Example 45. The method according to Example 44 when dependent on Example43, wherein forming the first semi-cylindrical shell from a first set ofthe panels comprises: providing a cradle comprising a first set of thering segments longitudinally spaced and aligned concentrically to form asemi-cylindrical frame conforming to the cylindrical shell; and laying afirst set of the panels in the cradle so as to abut respectivelongitudinal edges of each pair of adjacent panels to form the firstsemi-cylindrical shell.

Example 46. The method according to Example 43 or 45, or Example 44 whendependent on Example 43, wherein forming the second semi-cylindricalshell from a second set of the panels comprises: assembling a second setof the panels so as to abut respective longitudinal edges of each pairof adjacent panels to form the second semi-cylindrical shell.

Example 47. The method according to Example 46, wherein forming thequasi-cylindrical shell from the first semi-cylindrical shell, theextension panels, and the second semi-cylindrical shell comprises:laying the extension panels atop the first semi-cylindrical shell so asto abut respective longitudinal edges of the extension panels andcorresponding outermost adjacent panels of the first set of panels;laying the second semi-cylindrical shell atop the extension panels so asto abut respective longitudinal edges of the extension panels andcorresponding outermost adjacent panels of the second set of panels,wherein the abutting respective longitudinal edges of each pair ofadjacent panels forms a joint.

Example 48. The method according to Example 47, wherein the respectivelongitudinal edges of each pair of adjacent panels comprise a tongue anda groove, and the joint is formed by mating the tongue of one panel withthe groove of the abutting panel.

Example 49. The method according to any one of Examples 43 or 45 to 48,or Example 44 when dependent on Example 43, further comprising: afterforming the first semi-cylindrical shell from the first set of thepanels, and before forming the quasi-cylindrical shell from the firstsemi-cylindrical shell, the extension panels, and the secondsemi-cylindrical shell, placing at least one spacer in the firstsemi-cylindrical shell, the at least one spacer spacing at least some ofthe panels to maintain the quasi-cylindrical shape of thequasi-cylindrical shell.

Example 50. The method according to Example 49, wherein the at least onespacer has substantially a shape of the superimposition of a ‘U’ with aninverted ‘U’.

Example 51. The method according to Example 49 or 50, wherein placing atleast one spacer in the first semi-cylindrical shell comprises placingthe at least one spacer upright in the first semi-cylindrical shell soas to contact respective inside surfaces of at least some of the panelsof the first semi-cylindrical shell whereby the first semi-cylindricalshell supports the at least one spacer.

Example 52. The method according to any one of Examples 49 to 51,wherein forming the second semi-cylindrical shell from the second set ofthe panels, and forming the quasi-cylindrical shell from the firstsemi-cylindrical shell, the extension panels, and the secondsemi-cylindrical shell, further comprises: laying the second set of thepanels atop the extension panels and the at least one spacer so as toabut the respective longitudinal edges of each pair of the adjacentpanels to form the second semi-cylindrical shell atop the extensionpanels, and so as to abut the respective longitudinal edges of theoutermost panels for the second set of panels and the extension panels,wherein: the at least one spacer contacts respective inside surfaces ofat least some of the panels of the second semi-cylindrical shell,supports the second semi-cylindrical shell, and maintains a cylindricalshape of the cylindrical shell.

Example 53. The method according to any one of Examples 49 to 52,further comprising, after constricting the at least one collar tocompress the longitudinal joints formed at the abutting edges of pairsof adjacent panels, and before welding the respective inside seams ofthe joints when at the lower position: removing the at least one spacer,whereby an interior of the quasi-cylindrical shell is unobstructed.

Example 54. The method according to any one of Examples 49 to 53,wherein the at least one spacer comprises at least one spacing disk.

Example 55. The method according to Example 54, wherein the at least onespacing disk comprising a first semi-disk, a rectangular plate, and asecond semi-disk configured for rigid assembly to form the spacing diskand configured for disassembly, wherein removing the at least one spacercomprises disassembling the at least one spacing disk and removing thedisassembled at least one spacing disk from the interior of thequasi-cylindrical shell.

Example 56. The method according to any one of Examples 49 to 53,wherein the at least one spacer comprises at least one spacing ringcomprising a rim formed with an outer U-shaped channel sized and shapedfittingly to receive an inflatable tube.

Example 57. The method according to Example 56, wherein removing the atleast one spacer comprises deflating the inflatable tube to reducepressure between the inflatable tube and an inside surface of thequasi-cylindrical shell, and removal of the spacing ring from aninterior of the quasi-cylindrical shell.

Example 58. The method according to Example 44 or any one of Examples 45to 57 when dependent on Example 44, wherein forming the at least onecollar conformably encompassing the quasi-cylindrical shell comprises:laying a second set of the ring segments atop the quasi-cylindricalshell and above the first set of ring segments in pairwise fashion so asto oppose respective adjacent ends of each pair of ring segments therebyforming the collars conformably encompassing the quasi-cylindricalshell.

Example 59. The method according to Example 44 or any one of Examples 45to 58 when dependent on Example 44, wherein constricting the at leastone collar to compress the longitudinal joints formed at abutting edgesof pairs of adjacent panels comprises: clamping the quasi-cylindricalshell by constricting the collars using constricting means provided atthe opposing respective adjacent ends of each pair of ring segments,thereby compressing at least some of the pairs of longitudinal panels attheir respective joints.

Example 60. The method according to Example 41 or any one of Examples 42to 59 when dependent on Example 41, wherein moving the respective jointsof pairs of panels to the lower position, and welding the respectiveinside seams of the joints when at the lower position, comprisessequentially moving the respective joints of the pairs of panels to thelower position, and welding the inside seam of the joint when at thelower position.

Example 61. The method according to any one of Examples 39 to 60,further comprising, after welding the inside seams of the joints:removing the at least one collar from the quasi-cylindrical shell;moving the respective joints of the pairs of panels to an upperposition, and welding respective outside seams of the joints when at theupper position.

Example 62. The method according to Example 61, wherein moving therespective joints of pairs of panels to the upper position, and weldingthe respective outside seams of the joints when at the upper position,comprises sequentially moving the respective joints of the pairs ofpanels to the upper position, and welding the outside seam of the jointwhen at the upper position.

Example 63. The method according to any one of Examples 39 to 62,wherein moving the respective joints of pairs of panels to the lowerposition comprises rolling the quasi-cylindrical shell and at least onecollar to bring the respective joints of pairs of panels to the lowerposition.

Example 64. The method according to Example 61 or 62, wherein moving therespective joints of pairs of panels to the upper position comprisesrolling the quasi-cylindrical shell and at least one collar to bring therespective joints of pairs of panels to the upper position.

Example 65. The method according to Example 63 or 64, wherein rollingthe quasi-cylindrical shell and at least one collar comprises rollingthe quasi-cylindrical shell and at least one collar together about alongitudinal axis of the quasi-cylindrical shell.

Example 66. The method according to any one of Examples 63 to 65,wherein rolling the quasi-cylindrical shell and at least one collarcomprises rolling the quasi-cylindrical shell and at least one collartogether using a rolling apparatus.

Example 67. The method according to Example 66, wherein the rollingapparatus comprises a tank roller.

Example 68. The method according to any one of Examples 39 to 67,wherein at least one of the panels comprises a projection, and the atleast one collar comprises a recess sized and shaped fittingly toreceive the projection.

Example 69. The method according to Example 68, wherein the projectioncomprises a longitudinal rail.

Example 70. The method according to Example 37, 38, 41, or any one ofExamples 42 to 69 when dependent on Example 41, wherein the lowerposition is angularly displaced from a lowermost point by less than 90°.

Example 71. The method according to Example 37, 38, 41, or any one ofExamples 42 to 69 when dependent on Example 41, wherein the lowerposition is angularly displaced from a lowermost point by less than 70°.

Example 72. The method according to Example 37, 38, 41, or any one ofExamples 42 to 69 when dependent on Example 41, wherein the lowerposition is angularly displaced from a lowermost point by less than 45°.

Example 73. The method according to Example 37, 38, 41, or any one ofExamples 42 to 69 when dependent on Example 41, wherein the lowerposition is angularly displaced from a lowermost point by less than 10°.

Example 74. The method according to Example 37, 38, or 61, or any one of

Examples 62 to 73 when dependent on Example 61, wherein the upperposition is angularly displaced from an uppermost point by less than90°.

Example 75. The method according to Example 37, 38, or 61, or any one ofExamples 62 to 73 when dependent on Example 61, wherein the upperposition is angularly displaced from an uppermost point by less than70°.

Example 76. The method according to Example 37, 38, or 61, or any one ofExamples 62 to 73 when dependent on Example 61, wherein the upperposition is angularly displaced from an uppermost point by less than45°.

Example 77. The method according to Example 37, 38, or 61, or any one ofExamples 62 to 73 when dependent on Example 61, wherein the upperposition is angularly displaced from an uppermost point by less than10°.

Example 78. The method according to any one of Examples 37 to 77,wherein the quasi-cylindrical cargo container constitutes at least apart of a tanker truck, a tanker trailer, or a tanker railcar.

Example 79. The method according to any one of Examples 37 to 78,wherein, prior to welding the inside seams of the joints of the pairs ofpanels, the quasi-cylindrical shell is free, or substantially free, oftack welds.

Example 80. The method according to any one of Examples 37 to 79,wherein, prior to clamping the quasi-cylindrical shell by constrictingthe collars, the quasi-cylindrical shell is free, or substantially free,of tack welds.

Example 81. The method according to any one of Examples 37 to 80,wherein a transverse cross section of the quasi-cylindrical shell has ashape substantially of a ‘U’ superimposed with an inverted ‘U’.

Example 82. The method according to any one of Examples 38 to 81,wherein the at least two rigid, flat extension panels comprise twoextension panels having a common width.

Example 83. The method according to any one of Examples 38 to 81,wherein, at at least one lateral side of the quasi-cylindricalcontainer, the extension panels comprise a plurality of extensionpanels.

Example 84. The method according to Example 83, wherein the extensionpanels at a first lateral side of the quasi-cylindrical containertogether have a width common to the width of the extension panelstogether at a second lateral side of the quasi-cylindrical containerlaterally opposite the first lateral side.

Example 85. A quasi-cylindrical cargo container manufactured by themethod according to any one of Examples 1 to 84.

Example 86. A quasi-cylindrical cargo container formed of a plurality ofrigid panels into a quasi-cylindrical shell, wherein adjacent pairs ofthe panels are joined by single final welds and are free orsubstantially free of tack welds.

Example 87. The quasi-cylindrical cargo container according to Example86, wherein a transverse cross section of the quasi-cylindrical shellhas a shape substantially of a ‘U’ superimposed with an inverted ‘U’.

Example 88. An apparatus for manufacturing a cylindrical cargo containercomprising a quasi-cylindrical shell, the apparatus comprising: a cradlecomprising a first set of ring segments longitudinally spaced andaligned concentrically to form a semi-cylindrical frame; a second set ofring segments corresponding respectively pairwise to the first set ofring segments, wherein each pair of the first set of ring segments andthe second set of ring segments is configured for assembly to form acorresponding collar, to form a quasi-cylindrical frame from the cradleand the second set of ring segments; alignment guides provided at eachpair of opposable end faces of each pair of the first set of ringsegments and second set of ring segments to resist lateral misalignmentof the collar; and constricting means at at least one of the collars toconstrict the collar.

Example 89. The apparatus according to Example 88, comprisingconstricting means at a plurality of the collars.

Example 90. The apparatus according to Example 88 or 89, wherein thecradle further comprises at least one longitudinal frame member, whereinthe first set of ring segments are rigidly mounted on the at least onelongitudinal frame member to space the first set of ring segmentslongitudinally and align them concentrically.

Example 91. The apparatus according to any one of Examples 88 to 90,further comprising a rolling apparatus configured to roll thecylindrical frame about a longitudinal axis of the cylindrical frame.

Example 92. The apparatus according to Example 91, wherein the rollingapparatus comprises a tank roller.

Example 93. The apparatus according to any one of Examples 88 to 92further comprising at least one spacer to maintain a quasi-cylindricalshape of the quasi-cylindrical shell during manufacturing of thecylindrical cargo container.

Example 94. The apparatus according to Example 93, wherein the at leastone spacer comprises at least one spacing disk.

Example 95. The apparatus according to Example 94, wherein the at leastone spacing disk comprises a first semi-disk, a rectangular plate, and asecond semi-disk configured for rigid assembly to form the spacing diskand configured for disassembly.

Example 96. The apparatus according to Example 93, wherein the at leastone spacer comprises at least one spacing ring comprising an rim formedwith an outer U-shaped channel sized and shaped fittingly to receive aninflatable tube.

Example 97. The apparatus according to any one of Examples 88 to 96,wherein each collar has a shape substantially of a ‘U’ superimposed withan inverted ‘U’.

In the preceding description, for purposes of explanation, numerousdetails are set forth in order to provide a thorough understanding ofthe embodiments. However, it will be apparent to one skilled in the artthat these specific details are not required. In particular, it will beappreciated that the various additional features shown in the drawingsare generally optional unless specifically identified herein asrequired. The above-described embodiments are intended to be examplesonly. Alterations, modifications and variations can be effected to theparticular embodiments by those of skill in the art. The scope of theclaims should not be limited by the particular embodiments set forthherein, but should be construed in a manner consistent with thespecification as a whole.

What is claimed is:
 1. A method of manufacturing an obround cargocontainer, the method comprising: providing a plurality of longitudinalpanels formable into an obround shell having a transverse cross sectionwith an obround shape, the panels comprising: rigid curved panelsformable into a cylindrical shell, each curved panel comprising acylinder segment of the cylindrical shell; and at least two rigid, flatextension panels; forming the obround shell from the panels; forming atleast one collar conformably encompassing the obround shell;constricting the at least one collar to compress longitudinal jointsformed at abutting edges of pairs of adjacent panels; and weldingrespective joints of pairs of the panels.
 2. The method according toclaim 1, wherein welding the respective joints of pairs of the panelscomprises: moving the respective joints of the pairs of panels to alower position, and welding respective inside seams of the joints whenat the lower position.
 3. The method according to claim 2, whereinforming the obround shell from the panels comprises: forming a firstsemi-cylindrical shell from a first set of the curved panels; forming asecond semi-cylindrical shell from a second set of the curved panels;and forming the obround shell from the first semi-cylindrical shell, theextension panels, and the second semi-cylindrical shell.
 4. The methodaccording to claim 3, wherein each of the at least one collar comprisesa pair of ring segments formable into the collar sized and shapedconformably to encompass the obround shell.
 5. The method according toclaim 4, wherein forming the first semi-cylindrical shell from the firstset of the panels comprises: providing a cradle comprising a first setof the ring segments longitudinally spaced and aligned concentrically toform a semi-cylindrical frame conforming to the first semi-cylindricalshell; and laying the first set of the panels in the cradle so as toabut respective longitudinal edges of each pair of adjacent panels toform the first semi-cylindrical shell.
 6. The method according to claim5, wherein forming the second semi-cylindrical shell from the second setof the panels comprises: assembling the second set of the panels so asto abut respective longitudinal edges of each pair of adjacent panels toform the second semi-cylindrical shell.
 7. The method according to claim6, wherein forming the obround shell from the first semi-cylindricalshell, the extension panels, and the second semi-cylindrical shellcomprises: laying the extension panels atop the first semi-cylindricalshell so as to abut respective longitudinal edges of the extensionpanels and corresponding outermost adjacent panels of the first set ofpanels; and laying the second semi-cylindrical shell atop the extensionpanels so as to abut respective longitudinal edges of the extensionpanels and corresponding outermost adjacent panels of the second set ofpanels, wherein the abutting respective longitudinal edges of each pairof adjacent panels forms a joint.
 8. The method according to claim 7,wherein the respective longitudinal edges of each pair of adjacentpanels comprise a tongue and a groove, and the joint is formed by matingthe tongue of one panel with the groove of the abutting panel.
 9. Themethod according to claim 8, further comprising: after forming the firstsemi-cylindrical shell from the first set of the panels, and beforeforming the obround shell from the first semi-cylindrical shell, theextension panels, and the second semi-cylindrical shell, placing atleast one spacer in the first semi-cylindrical shell, the at least onespacer spacing at least some of the panels to maintain the obround shapeof the obround shell.
 10. The method according to claim 9, wherein theat least one spacer has an obround shape matching the obround shape ofthe transverse cross section of the obround shell.
 11. The methodaccording to claim 10, wherein placing the at least one spacer in thefirst semi-cylindrical shell comprises placing the at least one spacerupright in the first semi-cylindrical shell so as to contact respectiveinside surfaces of at least some of the panels of the firstsemi-cylindrical shell whereby the first semi-cylindrical shell supportsthe at least one spacer.
 12. The method according to claim 11, whereinforming the second semi-cylindrical shell from the second set of thepanels, and forming the obround shell from the first semi-cylindricalshell, the extension panels, and the second semi-cylindrical shell,further comprises: laying the second set of the panels atop theextension panels and the at least one spacer so as to abut therespective longitudinal edges of each pair of the adjacent panels toform the second semi-cylindrical shell atop the extension panels, and soas to abut the respective longitudinal edges of the outermost panels forthe second set of panels and the extension panels, wherein: the at leastone spacer contacts respective inside surfaces of at least some of thepanels of the second semi-cylindrical shell, supports the secondsemi-cylindrical shell, and maintains a semi-cylindrical shape of thesecond semi-cylindrical shell.
 13. The method according to claim 12,further comprising, after constricting the at least one collar tocompress the longitudinal joints formed at the abutting edges of pairsof adjacent panels, and before welding the respective inside seams ofthe joints when at the lower position: removing the at least one spacer,whereby an interior of the obround shell is unobstructed.
 14. The methodaccording to claim 13, wherein the at least one spacer comprises atleast one spacing disk, wherein the at least one spacing disk comprisesa first semi-disk, a rectangular plate, and a second semi-diskconfigured for rigid assembly to form the spacing disk and configuredfor disassembly, wherein removing the at least one spacer comprisesdisassembling the at least one spacing disk and removing thedisassembled at least one spacing disk from the interior of the obroundshell.
 15. The method according to claim 13, wherein the at least onespacer comprises at least one spacing ring comprising a rim formed withan outer U-shaped channel sized and shaped fittingly to receive aninflatable tube, wherein removing the at least one spacer comprisesdeflating the inflatable tube to reduce pressure between the inflatabletube and an inside surface of the obround shell, and removal of thespacing ring from an interior of the obround shell.
 16. The methodaccording to claim 7, wherein forming the at least one collarconformably encompassing the obround shell comprises: laying a secondset of the ring segments atop the obround shell and above the first setof ring segments in pairwise fashion so as to oppose respective adjacentends of each pair of ring segments thereby forming the collarsconformably encompassing the obround shell.
 17. The method according toclaim 16, wherein constricting the at least one collar to compress thelongitudinal joints formed at abutting edges of pairs of adjacent panelscomprises: clamping the obround shell by constricting the collars usingconstricting means provided at the opposing respective adjacent ends ofeach pair of ring segments, thereby compressing at least some of thepairs of longitudinal panels at their respective joints.
 18. The methodaccording to claim 2, further comprising, after welding the inside seamsof the joints: removing the at least one collar from the obround shell;moving the respective joints of the pairs of panels to an upperposition; and welding respective outside seams of the joints when at theupper position.
 19. The method according to claim 2, wherein moving therespective joints of pairs of panels to the lower position comprisesrolling the obround shell and at least one collar to bring therespective joints of pairs of panels to the lower position, whereinrolling the obround shell and at least one collar comprises rolling theobround shell and at least one collar together about a longitudinal axisof the obround shell, wherein rolling the obround shell and at least onecollar comprises rolling the obround shell and at least one collartogether using a rolling apparatus.
 20. The method according to claim19, wherein the rolling apparatus comprises a tank roller.
 21. Themethod according to claim 2, wherein, prior to welding the inside seamsof the joints of the pairs of panels, the obround shell is free, orsubstantially free, of tack welds.
 22. The method according to claim 1,wherein, prior to constricting the collars, the obround shell is free,or substantially free, of tack welds.